Methods and apparatus for optimizing paging mechanisms using device context information

ABSTRACT

Methods and apparatus enabling a wireless network to optimize paging channel operation, based on mobile device context information. In one embodiment, the wireless network is a cellular network (e.g., LTE-Advanced), and both base stations and cellular user devices dynamically exchange and maintain a paging agreement. The paging agreement limits the paging channel operation, thereby minimizing unnecessary scanning and usage of irrelevant radio resources. Such paging mechanisms are limited to the air interface between the base station and the mobile device, and are compatible with existing legacy devices and network entities. Networks with appropriately enabled user devices may improve their resource utilization. Base stations may advantageously reclaim freed-up cellular resources to support other services.

The present application is a continuation application of U.S. patentapplication Ser. No. 12/610,145, filed Oct. 30, 2009, which isincorporated herein by reference in its entirety. This application isrelated to co-owned and co-pending U.S. patent application Ser. No.12/409,398 filed Mar. 23, 2009 and entitled “Methods and Apparatus forOptimizing Paging Mechanisms and Publication of Dynamic PagingMechanisms”, which is incorporated herein by reference in its entirety.

RELATED APPLICATIONS

This application is related to co-owned and co-pending U.S. patentapplication Ser. No. 12/409,398 filed Mar. 23, 2009 and entitled“Methods and Apparatus for Optimizing Paging Mechanisms and Publicationof Dynamic Paging Mechanisms”, which is incorporated herein by referencein its entirety.

COPYRIGHT

A portion of the disclosure of this patent document contains materialthat is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent files or records, but otherwise reserves all copyrightrights whatsoever.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates generally to the field of wirelesscommunication and data networks. More particularly, in one exemplaryaspect, the present invention is directed to methods and apparatus foroptimizing paging transmissions in a wireless communication and datanetwork based on mobile device context information.

2. Description of Related Technology

Universal Mobile Telecommunications System (UMTS) is an exemplaryimplementation of a “third-generation” or “3G” cellular telephonetechnology. The UMTS standard is specified by a collaborative bodyreferred to as the 3^(rd) Generation Partnership Project (3GPP). The3GPP has adopted UMTS as a 3G cellular radio system targeted for interalia European markets, in response to requirements set forth by theInternational Telecommunications Union (ITU). The ITU standardizes andregulates international radio and telecommunications. Enhancements toUMTS will support future evolution to fourth generation (4G) technology.

A current topic of interest is the further development of UMTS towards amobile radio communication system optimized for packet data transmissionthrough improved system capacity and spectral efficiency. In the contextof 3GPP, the activities in this regard are summarized under the generalterm “LTE” (for Long Term Evolution). The aim is, among others, toincrease the maximum net transmission rate significantly in the future,namely to speeds on the order of 300 Mbps in the downlink transmissiondirection and 75 Mbps in the uplink transmission direction.

Further advancements of 3GPP are being investigated within LTE towardsan LMT-Advanced radio interface technology, referred to as“LTE-Advanced” or “LTE-A”. Details regarding scope and objectives of theLTE-Advanced study are described at, inter alia; RP-080137 entitled“Further advancements for E-UTRA (LTE-Advanced)” to NTT DoCoMo et al.,the contents of which are incorporated herein by reference in itsentirety. The IMT-Advanced activities have been commenced and are guidedby ITU-R (International Telecommunications Union—Radio CommunicationSector). Key features to be supported by candidate IMT-Advanced systemshave been set by ITU-R and include amongst others: (1) high qualitymobile services; (2) worldwide roaming capability; and (3) peak datarates of one hundred (100) Mbps for high mobility environments, and ofone (1) Gbps for low mobility environments.

The current discussions in 3GPP related to LTE-A are focused on thetechnologies to further evolve LTE in terms of spectral efficiency, celledge throughput, coverage and latency based on the requirements in 3GPPTS 36.913: “Requirements for further advancements for E-UTRA(LTE-Advanced)”, the contents of which are incorporated herein byreference in its entirety. Candidate technologies include (1) multi-hopRelay; (2) downlink network Multiple Input Multiple Output (MIMO)antenna technologies; (3) support for bandwidths greater than twenty(20) MHz by spectrum aggregation; (4) flexible spectrum usage/spectrumsharing; and (5) intercell interference management. Backwardcompatibility with legacy LTE networks is also an important requirementfor future LTE-A networks, i.e. an LTE-A network also supports LTE UserEquipment (UE), and an LTE-A UE can operate in an LTE network.

Prior Art Paging Mechanisms—

Paging mechanisms are used in many prior art cellular mobile radiocommunication systems such as UMTS and LTE. Paging mechanisms allow amobile device to minimize power consumption by operating in a reduced or“idle” state while unused. Once a UE receives a paging notification, it“wakes up” to respond to the notification.

Various approaches to paging mechanisms within wireless systems areevidenced in the prior art. For example, within most cellular networks,the network operator maintains an approximate location or “TrackingArea” (TA) for idle mobile devices. Each TA consists of several cells.When a mobile device is paged, all assigned cells within the TA transmitthe paging notification. Presumably, as long as the mobile device hasnot moved out of the TA, it should receive the paging notification.Unfortunately, larger tracking areas that provide better paging coveragealso consume proportionately more radio spectrum and resources; thus theprior art solutions trade coverage area for resource utilization.

Incipient LTE-A networks flexibly fragment and/or aggregate spectrumbandwidths freely. Regrettably however, such spectrum flexibilityconsiderably complicates paging; as a UE moves through a tracking area,the bandwidth usage may vary widely. For example, the UE is generallyunaware of the resource configuration used for paging messaging.Similarly, the network does not know which resources the UE ismonitoring for paging channel reception. Thus, existing networkstransmit paging channel messages over the entire cell bandwidth for eachcell of the TA, until contact with the mobile device is re-established.

Accordingly, suitable paging mechanisms are needed to specificallyaddress networks having fragmented multi-hand operational capabilities,and flexible resourcing. Such an improved solution should ideallyoperate seamlessly and without adversely impacting user experience onexisting radio apparatus, and that of other wireless devices (i.e.,remaining backward compatible).

Improved apparatus and methods for paging mechanisms specificallyaddressing the complexities of the new LTE-Advanced architecture arealso needed. The LTE-Advanced system architecture combines fragmentedmultiband capabilities, OFDM access, and mixed populations of legacy andnewer UEs. Existing mechanisms for paging within this architecture areless than optimal.

SUMMARY OF THE INVENTION

The present invention satisfies the aforementioned needs by providingimproved apparatus and methods for paging in a wireless network. In oneaspect of the invention, a method of paging a mobile device from a basestation in a wireless network is disclosed. In one embodiment, thepaging is based on a selected resource used by the mobile device toreceive a paging channel, and the method includes: receiving informationregarding a resource used by the mobile device when the mobile deviceselects that resource; and sending paging information to the mobiledevice from the base station using only a paging channel of the usedresource. If no used resource information exists, no paging informationis sent to the mobile device.

In one variant, the base station includes an LTE-compliant eNodeB, andthe mobile device is an LTE-compliant UE, and the selected resourceincludes at least one component carrier (CC).

In another variant, the base station is an LTE-A (Long TermEvolution-Advanced)-compliant eNodeB which is configured to support a20-MHz maximum bandwidth for the at least one component carrier, so asto maintain backward compatibility with extant LTE apparatus. Theselected resource used by the mobile device to receive the pagingchannel is used in an idle (non-connected) mode.

In a second aspect of the invention, a base station apparatus isdisclosed. In one embodiment, the apparatus includes: a digitalprocessor; a radio interface in data communication with the processor;and a storage device in data communication with the processor, thestorage device comprising computer-executable instructions that, whenexecuted by the digital processor: (i) responsive to receiving an updatemessage from a mobile device via the radio interface: negotiate a pagingagreement with the mobile device; and start a timing function; (ii)responsive to receiving an indication via the radio interface, reset thetiming function; and (iii) responsive to the timing function expiring,delete the paging agreement.

In one variant, the apparatus further includes a broadband interface indata communication with the processor; and wherein responsive toreceiving a network page addressed to the mobile device via thebroadband interface. The apparatus further: determines the existence ofthe paging agreement; if the paging agreement does not exist, ignoresthe network page; and if the paging agreement exists, transmits a pagingchannel message to the mobile device based on the paging agreement.

In another variant, the indication includes a substantially periodicheartbeat message, and the timing function is a watchdog timer.

In yet another variant, the base station apparatus and the mobile deviceare each LTE-A (Long Term Evolution—Advanced) compliant.

In a third aspect of the invention, a mobile communication apparatus isdisclosed. In one embodiment, the apparatus includes: a digitalprocessor; a wireless interface in data communication with theprocessor; and a storage device in data communication with theprocessor, the storage device comprising computer-executableinstructions. When executed by the digital processor, the instructions:cause transmission of an update message, the update message configuredto cause a receiver thereof to generate a paging agreement, and invoke atiming function having a first schedule; and cause transmission of asecond message having a second schedule different than the firstschedule, the second message being configured to cause extension of thepaging agreement.

In one variant, the second message is further configured to cause thereceiving base station to restart the timing function.

In another variant, the paging agreement includes a specification of atleast: (i) a component carrier to be used for paging the mobileapparatus; and (ii) at least one timing parameter to be used forperiodic transmission of the second message.

In a fourth aspect of the invention, a method of efficientlytransmitting paging messages is disclosed. In one embodiment, themessages are transmitted to a mobile device from a plurality of basestations of a wireless network, and the method includes: within a subsetof the base stations, generating a paging agreement between at least onebase station and the mobile device, the at least one base station beingpart of the subset; storing context information at the at least one basestation; receiving data for the mobile device at the subset of theplurality of base stations; and transmitting a paging message from onlythe at least one base station having the generated paging agreement.

In one variant, the context information includes a description of atleast one paging resource available to the mobile device.

In another variant, the mobile device is operating in an idle,unconnected mode.

In a fifth aspect of the invention, a method of conducting pagingoperations in a multi-cell network is disclosed. In one embodiment, themethod includes: designating a tracking area having a plurality of basestations associated therewith; associating a mobile device with thetracking area; and specifying, using at least the mobile device, only asubset of the plurality of base stations to perform paging of the mobiledevice.

In one variant, the network includes a core portion in operativecommunication with the plurality of base stations, the core portion notbeing appraised of the specification of the subset of base stations. Themobile device and base stations are Long-Term Evolution-Advanced.(LTE-A) compliant, and the core portion is LTE compliant, and notLong-Term Evolution-Advanced (LTE-A) compliant.

In a sixth aspect of the invention, a computer readable apparatus isdisclosed. In one embodiment, the apparatus includes a storage mediumhaving at least one computer program, the at least one program beingconfigured to enable power-efficient paging operations for a mobiledevice within a cellular network.

In a seventh aspect of the invention, a wireless network is disclosed.In one embodiment, the network is an LTE-compliant cellular network,with portions of the network (i.e., base stations and UEs) beingcompliant with LTE-A so that the benefits of LTE-A can be realized, yetwith power- and resource-efficient paging mode operation.

Other features and advantages of the present invention will immediatelybe recognized by persons of ordinary skill in the art with reference tothe attached drawings and detailed description of exemplary embodimentsas given below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is time and frequency plot of a typical prior art Time DivisionMultiple Access (TDMA) implementation.

FIG. 1B is time and frequency plot of a typical prior art FrequencyDivision Multiple Access (FDMA) implementation.

FIG. 1C is time and frequency plot of a typical prior art Code DivisionMultiple Access (CDMA) implementation.

FIG. 1D is time and frequency plot of a typical prior art OrthogonalFrequency-Division Multiple Access (OFDMA) implementation used incombination with TDMA.

FIG. 2 is a graphical representation of various prior art duplex methodsincluding full-duplex FDD, half-duplex FDD and TDD.

FIG. 3 is a graphical representation of an exemplary frame structuretype for a prior art LTE FDD system:

FIG. 4 is a graphical representation of a prior art LTE two-phase pagingmechanism timing.

FIG. 5 is a graphical representation of the timing of a prior art LTE-Atwo-phase paging mechanism.

FIG. 6 is a graphical illustration of a prior art cellular systemtransmitting paging notifications to a mobile device.

FIG. 7 is a graphical illustration of an exemplary cellular systemtransmitting paging notifications to a mobile device, in accordance withone embodiment of the invention.

FIG. 8 is a logical flow diagram of one exemplary embodiment of thegeneralized method for establishing and maintaining paging agreement inaccordance with the invention.

FIG. 9 is a ladder diagram further describing the methods forestablishing paging agreement between multiple parties in a cellularradio system, in accordance with the generalized methods of FIG. 8.

FIG. 10 is a logical flow diagram of one exemplary embodiment of thegeneralized method for efficiently using context information to transmitpaging channel messages, in accordance with the invention.

FIG. 11 is a ladder diagram further describing the methods for paging amobile device using context information, in accordance with thegeneralized methods of FIG. 10.

FIG. 12 is a functional block diagram illustrating one embodiment of abase station apparatus adapted to implement the methods of the presentinvention.

FIG. 13 is a graphical representation of one embodiment of an updatemessage format containing context information, in accordance with theprinciples of the present invention.

FIG. 14 is a graphical representation of one embodiment of anacknowledgement message format containing a paging agreement, inaccordance with the principles of the present invention.

FIG. 14A is a graphical representation of one embodiment of a pagingagreement entry stored at one exemplary eNB, in accordance with theprinciples of the present invention.

FIG. 15 is a functional block diagram illustrating one embodiment of aclient device (e.g., UE) adapted to implement the methods of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to the drawings, wherein like numerals refer tolike parts throughout.

Overview

In one aspect, the present invention discloses methods and apparatus formodifying paging channel operation within wireless communicationssystems based on context information. This feature allows, for example,base stations to significantly reduce bandwidth used for pagingoperations. In one embodiment, a paging agreement is exchanged between abase station of a tracking area and a mobile device. The base stationand mobile device conform to the paging agreement for future pagingchannel transactions (e.g., appropriate component carriers, timing,etc.). Additional features are disclosed for automatically ensuringpaging agreement validity.

Such methods and apparatus are particularly useful for addressing themanagement of paging capabilities within networks having fragmentedmulti-band operational capabilities, and flexible resourceallocation/utilization such as, inter alia, LTE-Advanced architectures.

In one implementation of the invention, mobile device contextinformation includes one or more of mobile device identity, hardwareversion, default refresh timer period, one or more suggested radioresources, base station reception information, etc. Context informationis evaluated by the base station to determine a paging agreement. Insome embodiments, a mobile device may simultaneously maintain multiplepaging agreements with multiple base stations.

In another aspect of the invention, methods and apparatus are disclosedwherein paging agreements are periodically refreshed, either by themobile device or the base station. In some embodiments, pagingagreements that are not refreshed are terminated. In alternateembodiments, paging agreements that are not refreshed trigger revivalprocedures, to recover the original paging agreement. More generally,broader solutions for unexpected behaviors of paging agreements aredisclosed. In some implementations, inconsistent paging behavior (withrespect to the paging agreement) terminates the paging agreement.Similarly, inconsistent paging behavior may also trigger revival orrecovery actions, such as retry attempts for paging message delivery.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention are now described indetail. While these embodiments are primarily discussed in the contextof a UMTS wireless network, and more specifically in one variant tofourth-generation (“4G”) UMTS, LTE and LTE-A networks, it will berecognized by those of ordinary skill that the present invention is notso limited. In fact, the various aspects of the invention are useful inany wireless system (e.g., cellular networks, wireless local areanetworks, ad hoc connections, etc.) that can benefit from the pagingmechanisms described herein. Examples of such wireless systems includeWi-Fi™, WiMAX™, Bluetooth™, etc.

In the following discussion of the exemplary embodiments of theinvention, a cellular radio system includes a network of radio cellseach served by a transmitting station, known as a cell site or basestation. The radio network provides wireless communications service fora plurality of transceivers (in most cases mobile). The network of basestations working in collaboration allows for wireless service which isgreater than the radio coverage provided by a single serving basestation. The individual base stations are connected by another network(in many eases a wired network), which includes additional controllersfor resource management and in some cases access to other networksystems (such as the Internet) or MANs.

In LTE there are two (2) distinct types of base stations: eNodeB (eNB),and Home eNodeB (HNB). In prior cellular networks, the network of basestations was owned and or controlled by a single network operatorentity. The 3GPP has introduced a new network element known as “HomeNode B” (HNB). A Home Base Station (or Home NodeB (HNB), or Home eNodeB(HeNB) in 3GPP terminology) is a base station optimized for use inresidential, corporate, or similar environments (e.g., private homes,public restaurants, small offices, enterprises, hospitals, etc., andhence the tom “home” is not meant to be limiting to residentialapplications). In the present context, the terms “Home Base Station”,“Home NodeB” (for UMTS), “Home eNodeB” (for LTE) refer generally to a“femtocell”. In the present context, the terms base station, “NodeB”,and “eNodeB” (for LTE) refer generally to a “macrocell”.

Long Term Evolution (LTE) Access Methods

The current LTE specification defines several flexible multiple accessmethods to improve transmission over the air interface to increasepotential transmission rates. LTE specifies Orthogonal FrequencyDivision Multiple Access (OFDMA) in combination with Time DivisionMultiple Access (TDMA) for downlink access. This hybrid access techniquesubsequently also called OFDMA/TDMA, is a multi-carrier multiple accessmethod in which a subscriber is provided with a defined number ofsubcarriers in the frequency spectrum and a defined transmission timefor the purpose of data transmission. LTE further specifies SC-FDMA(Single Carrier Frequency Division Multiple Access) in combination withTDMA for uplink access. Furthermore, LTE supports full-duplex FDD(frequency division duplexing), half-duplex FDD and TDD (time divisionduplexing). Lastly, LTE supports scalable bandwidth segments of onepoint four (L4), three (3), five (5), ten (10), fifteen (15) and twenty(20) MHz.

Briefly, FIGS. 1A-1D summarize basic multiple access methods wellunderstood in the wireless transmission arts, and used throughout thisdisclosure. In these figures, it will be recognized that time increasesin the direction of a time axis (t), and frequency increases in thedirection of a frequency axis (F).

FIG. 1A is a first time-frequency diagram illustrating a TDMA (timedivision multiple access) system. In TDMA, each mobile radio terminalmay use the whole frequency band provided for the usage by the mobileradio terminals. However, for each mobile radio device, only apredefined transmission time interval (TTI) is allocated in which themobile radio device may send and receive useful data. During atransmission time interval 102, only one mobile radio device is activein a radio cell.

FIG. 1B is a second time-frequency diagram illustrating a FDMA(frequency division multiple access) system. In FDMA, each mobile radiodevice may freely use the time domain, but only a predefined (narrow)frequency band 104 within the entire frequency band is available forsending and receiving useful data. Only one mobile radio device isactive in each narrow frequency band of the radio cell at any giventime.

FIG. 1C is a third time-frequency diagram illustrating a CDMA (codedivision multiple access) system. In CDMA (a sub-species of so-called“direct sequence” or DS systems), each mobile radio terminal may sendand receive useful data during any time period, and may use the entireavailable frequency band. In order to avoid interference between thedata sent by different senders, each mobile radio device is allocated abinary pseudo-noise code pattern 106. The code patterns which areallocated to the different mobile radio terminals are ideallyorthogonal, and data sent by a mobile radio terminal or to be receivedby the mobile radio terminal is coded (“spread”) by the code patternallocated to the mobile radio terminal.

FIG. 1D illustrates an OFDMA (orthogonal frequency division multipleaccess) system in combination with TDMA. OFDMA is a special case of FDMAadd is a multiple carrier method in which the entire frequency bandhaving a bandwidth B is subdivided into M orthogonal sub-carriers 108.Thus, there are M (narrow) frequency bands each with a bandwidth ofF=B/M. In OFDMA, a data stream to be sent is divided over a multiplicityof sub-carriers, and is transmitted (generally) in parallel. The datarate of each sub-carrier is accordingly lower than the overall datarate. For each mobile radio terminal, a defined number of sub-carriers108 are allocated for data transmission. A chief advantage of OFDMA'sflexible time-frequency resource allocation, over e.g., CDMA's flexiblecode allocation, is a higher spectral efficiency (i.e., more bits perunit time per unit of frequency bandwidth).

In LTE, downlink access based on OFDMA/TDMA data streams is subdividedin time to constant time intervals, or frames. Each frame is furthersubdivided into slots, and subframes. Not all subframes need to be inuse (the network could be underutilized), but a subframe is the smallestincremental amount of time to be used for data transmission/receptionwith the transceivers. Once a transceiver has acquired the base stationtiming, subframes are allocated to each transceiver with a schedulingfunction.

FIG. 2 illustrates the aforementioned full-duplex FDD, half-duplex FDDand TDD according to the prior art. Full-duplex FDD uses two separatefrequency bands for uplink 222 and downlink 220 transmissions, whereboth transmissions can occur simultaneously. Unlike FDD, TDD uses thesame frequency band for transmission in both uplink 222 and downlink220; however within a given time frame, the direction of transmission isswitched alternatively between the downlink 220 and uplink 222. Halfduplex FDD uses two separate frequency bands for uplink 222 and downlink220 transmissions, similar to full-duplex FDD, but uplink and downlinktransmissions are non-overlapping in time (similar to TDD).

LTE networks utilize a standard frame structure type 1 (one) 300 (asshown in FIG. 3) which is used in both full-duplex and half-duplex FDD.Each radio frame 302 is ten (10) ms in duration, and consists of twenty(20) slots 304 in 0.5 ms length intervals, numbered from 0 to 19. Asubframe 306 is defined as two (2) consecutive slots 304. For FDD, ten(10) subframes are available for downlink transmission and ten (10)subframes are available for uplink transmissions in each ten (10) msinterval. Uplink and downlink transmissions are separated in thefrequency domain. Depending on the slot format, a subframe consists offourteen (14) or twelve (12) OFDMA symbols in downlink, and fourteen(14) or twelve (12) SC-FDMA symbols in uplink, respectively. Details offrame structure and timing are described in 3GPP TS 36.211 entitled“E-UTRA—Physical channels and modulation”, the contents of which areincorporated herein by reference in its entirety.

Referring now to FIG. 4, two-stage paging channel messaging 400 isillustrated for prior art LTE networks. In LTE networks, the first OFDMAsymbols are used for transmitting three (3) kinds of “control channels”:the PCFICH, PDCCH, and PHICH. The “Physical Control Format IndicatorChannel” (PCFICH) indicates the format of the Physical Downlink ControlChannel (PDCCH). The PDCCH carries, inter alia, resource assignments andpaging messages. The Physical HARQ Indicator Channel (PHICH) is used foracknowledging or not-acknowledging (ACK/NACK) data received from themobile device in the Physical Uplink Shared Channel (PUSCH). Each ofthese control channels are divided in groups of four (4) subcarriers andspread over the entire LTE system bandwidth.

As shown, the UE monitors the Physical Downlink Control Channel (PDCCH)402 at defined time instants (i.e., defined subframes of length 1 ms). Apaging identifier is assigned to the UE by the network. When theassigned paging identifier is decoded on the PDCCH, the UE decodes theassociated Physical Downlink Shared Channel (PDSCH) 404. As shown, thePDCCH is transmitted in subframe #i+2; occupying one (1), two (2), orthree (3) OFDMA symbols of the first slot, where the number of symbolsis dynamically adjusted by network. The PDSCH 404 is transmitted in theremainder of subframe #i+2, and occupies the OFDMA symbols in thesubframe that are not used by the PDCCH, PCFICH or PHICH.

Improvements For Long Term Evolution-Advanced (LTE-A)—

Within the framework of existing LTE architectures and access methods,incipient LTE-A proposals will continue to expand the versatility ofexisting LTE operation, by providing bandwidths up to 100 MHz withspectrum aggregation. For example, the bandwidth of an LTE-A cell may becomposed of any number of spectral slices hereinafter referred to as“Component Carriers” (CC). However, in order to maintain backwardcompatibility between LTE and LTE-A networks (i.e., an LTE-A eNodeB mustalso support LTE user equipment), each CC is maximally limited to 20 MHz(a LTE limitation).

FIG. 5 is a graphical illustration of one prior art LTE-A schedule ofthe two-stage paging channel messaging 500, shown with respect tofrequency and time. In LTE-A, the component carrier in LTE-A isequivalent to the entire system bandwidth of an LTE system. For example,in LTE-A, the bandwidth of each CC 502 may span up to twenty (20) MHz ofbandwidth. Several CCs are offered simultaneously by the LTE-A cell,covering a much larger aggregate bandwidth. LTE-A UEs may use severalCCs simultaneously whereas LTE UEs can use only the equivalent of one(1) CC at a time. This channel structure retains full backwardcompatibility for LTE UEs, while enabling much larger bandwidthpossibilities for LTE-A UEs.

While the proposed enhancements for LTE-A greatly benefits UEs withongoing connections, these same enhancements have undesirablerepercussions for unconnected UEs. During “idle” mode (i.e., when the UEis not connected to the network), the UE must periodically check thepaging channel for status updates e.g., pending calls, Short MessagingService (SMS), data updates, etc. However, since there is no ongoingdialog established between the UE and the radio access network duringidle modes, the UE and the eNB may not necessarily agree on pagingchannel parameters. Thus, the UE must check all paging channels on allpossible CC slices. Similarly, the tracking area eNBs of the radioaccess network must actively broadcast paging channel messages on anysuitable CCs. These CCs are hereinafter referred to as “active ComponentCarriers (CCs)”. In some implementations, a CC may be excluded frompaging operation (such non-active CCs are oily used if the eNB assignsthe resources to a LTE-A UE). Excluded CCs are not compatible with LTEUEs. Clearly, both receiving and transmitting a simple paging messageover large expanses of spectrum is not optimal.

FIG. 6 further illustrates the previously mentioned deficiencies of theprior art paging channel transmission 600. As shown, the tracking area(TA) consists of three (3) eNBs 602: eNB1, eNB2, and eNB3. The threeeNBs have a backhaul connection to a Mobility Management Entity (MME)604, where the MME maintains a listing of all currently known UEs withinthe TA (including UE1 606). To initiate a data transmission, the MMEtransmits a network page 610 via the backhaul to each of the eNBs of theTA. Responsively, each eNB transmits a paging notification to the UE ontheir active CCs (air interface paging channel message 612).

As a brief aside, the terms “paging message”, “paging notification”,“paging channel message”, etc. have generally been used heretoforeinterchangeably. Prior art terminology does not differentiate betweenthe various incarnations of the paging message (from generation withinthe Core Network to reception at the User Equipment). However, in thefollowing discussions, the aforementioned interpretation is impreciseand may be potentially confusing. Thus, as used hereinafter, the terms“paging request” and “network page” refer to the page-related messagingbetween the central network entity (e.g., the MME) and the intermediaryserving device (e.g., eNB). In contrast, the terms “paging Message”,“paging notification”, “paging channel”, “paging transmission” refer tothe page-related messaging sent via the air interface from theintermediary serving device to the mobile device. The terms “pagingmechanism”, “paging”, and “paged” refer to the overall paging process,and does not imply limitation to either the network or air interfaces.

Referring back to FIG. 6, in the prior art paging transmission system600, UE1 606 receives the paging channel message 612 from eNB1 602. Thepaging channel messages transmitted by the other eNBs (eNB2, eNB3) arewasted, and consume precious radio resources. Even within the coverageof eNB1, the UE receives paging messages on each CC of eNB1. The UE onlyneeds to receive a single paging channel message; thus, the duplicativepaging channel messages are gratuitous as well.

Example Operation—

The following discussion illustrates various useful aspects of thepresent invention for optimizing paging mechanisms, based on usercontext information.

FIG. 7 depicts one exemplary embodiment of a paging system 700 accordingto the invention. As shown, the tracking area (TA) consists of three (3)eNBs 1200: eNB4, eNB5, and eNB6. The three (3) eNBs have a backhaulconnection to a Mobility Management Entity (MME) 604, where the MMEmaintains a listing of all currently known UEs within the TA (includingthe invention-enabled UE2 1500).

Upon initial detection of a nearby suitable eNB4 1200, or duringsubsequent context information changes, the UE2 1500 transmits a firstupdate message to the eNB4, the update message contains contextinformation (e.g., various supported options, timer options, etc.)useful for creating a paging agreement. In response to the updatemessage, the eNB4 transmits an acknowledgment message (e.g., selectionof one or more options, timer settings, etc.). Once the acknowledgementmessage is received, the two parties have finalized the pagingagreement, notably without network assistance (the entire transactionoccurs between only the UE2 and the eNB4, without requiring higher CoreNetwork participation). The paging agreement identifies the active CCthat the eNB4 and UE2 will use for paging channel messages.

To ensure validity of the paging agreement, the UE2 and eNB4periodically refresh the paging agreement, using in one variant a“heartbeat” or “service pulse” message, A “watchdog” timer triggerscorrective action if a heartbeat is missed; a missed heartbeat couldeither indicate momentary radio link interference, or alternatively,termination of the paging agreement. In this scenario, if the UE (UE2)does not refresh the timer, then the eNB4 assumes that the UE2 has movedto another eNB (eNB5, eNB6) within the TA, and deletes the UE2's record.

As described in greater detail hereinafter, the context information mayarbitrarily change. Changes to context information may or may not havean impact on the paging agreement. Notification of context change may besignalled via the described update or acknowledge messages. The eNB4stores the context information for each UE2, and if necessary alters thepaging agreement. Such changes can be triggered by the eNB4 (e.g. the CCshould no longer be used by UEs in idle mode, etc.), or by the UE2 (e.g.in case it detects a CC which is more suitable, etc.).

During a page, the MME 604 transmits a network page 610 via the backhaulto each of the inventive eNBs of the TA. In contrast to the prior artscheme 600 of FIG. 6, each of the invention-enabled eNBs 1200 locallyretains context information and paging agreements regarding the UEs 1500within their coverage area (generally a subset of the tracking area).Consequently, upon receiving the network page, each eNB consults itsinternal database of current context information. If the paged UE doesnot match any of their recorded UEs, then the network page 610 isignored. If the eNB has a successful match, then the eNB transmits apaging channel message 702. Thus, only eNB4 transmits a paging channelmessage 702 to the invention enabled UE2 1500 via the proper CC; allother eNBs radio resources are free for other tasks, thereby improvingoverall network efficiency.

Moreover, the foregoing embodiment advantageously is fully backwardcompatible solution with existing LTE and/or LTE-A networks. Forexample, existing MME 604 and associated messaging interfaces can remainunchanged. Also, invention-enabled eNBs 1200 can be freely interspersedwith legacy eNBs 602, as the paging scheme described herein does notrequire (but none-the-less can utilize if desired) cooperation betweenbase stations. Similarly, eNBs 1200 and UEs 1500 configured according tothe present invention may freely mingle with their legacy counterpartsby using revision information (included in one embodiment within contextinformation records).

Methods—

FIGS. 8 and 10 are logical flow diagrams illustrating two (2) distinctaspects of wireless paging based on context information, in accordancewith exemplary embodiments of the present invention. FIG. 8 generallydescribes processes for updating the context information and/or pagingagreements of wireless devices operating within a wireless network. FIG.10 broadly characterizes paging mechanisms that exploit a pagingagreement.

Establishing, and Maintaining Paging Agreement—

FIG. 8 illustrates a generalized method for maintaining paging agreementbetween multiple parties in a cellular radio system. Specifically, asshown in the method 800 of FIG. 8, the participating parties are firstidentified at step 802. In one exemplary embodiment, a first mobiledevice identifies one or more second base station devices. Suchidentification may be based on a publicly broadcast signal, such as apilot channel, broadcast channel, etc. For example, LTE radio accessnetworks publicly broadcast system information in System InformationBlocks (SIB), or Master Information Blocks (MIB). An enabled UE 1500decodes the SIBs of nearby eNBs (1200, 602). If the eNB supportsenhanced paging channel operations (in accordance with the presentinvention) then the UE proceeds to step 804. Otherwise, the UE resumeslegacy idle mode procedures. Similar methods are applicable for theeNBs, for example, an eNB that receives an enhanced message from an UE(e.g. a “Tracking Area Update”), may configure itself for enhancedpaging procedures. If the eNB receives a legacy message from the UE,then it reverts to legacy paging procedures.

Moreover, in certain crowded networks, the mobile device may detectseveral candidate base stations. Conceivably, the candidate basestations may have a wide array of capabilities, spanning variousgradations from legacy, enhanced, and perhaps even future incarnationsof other paging channel operations. Accordingly, in certainimplementations, the mobile device can select one or more of thecandidate base stations for context information exchange, and pagingagreement (step 804).

In other embodiments, the one or more second base station devicesidentify the first mobile device. Such identification may be performedby checking one or more device attributes. For example, a mobile devicewithin the coverage of a base station may be queried for enhanced pagingchannel capabilities. Similarly, in other variations, the base stationmay discover enhanced mobile device operation via other methods e.g.,out-of-band signaling, communication with a network management entity,etc.

The most efficient usage of network resources would dictate the fewestnumber of radio resources (e.g., a CC) to robustly transmit a pagingmessage to the mobile device. Thus, in one embodiment, the identifiedparties agree on a number of radio resources for paging transmission.For example, in cases of very clear reception, perhaps only a single eNBtransmitting paging messages on a single CC is sufficient. In contrast,in cases of muddled reception (due to e.g., high-fade environments, veryhigh user density, etc.), multiple base stations may be required to useone or more CCs to transmit paging notifications.

At step 804, the identified parties exchange context information and/orpaging Agreements. In LTE networks, a reliable exchange of contextinformation is conducted over an established connection. LTE networksonly support a single Radio Resource Connection (RRC) for any at anytime. In most cellular systems, connection establishment requiressignificant amounts of control layer signaling including authentication,authorization, registration, etc. Each of these network transactionswould be duplicated for each base station the mobile device exchangescontext information with. Accordingly, in alternate embodiments of thepresent invention, the device transmits a simple update messagecontaining its context information, to each member of the Tracking Area(TA) without connection establishment. Such an embodiment would reducethe necessary requirements for control layer signaling.

In certain radio access technologies, network connection is muchsimpler. Thus, in some embodiments, context information may bepreferably exchanged using network connections. For example, ad hocnetworking generally provides radio connection to IP-based networks(Internet Protocol), without requiring complex registration procedures.Similarly, future home networking applications may IP-based services(Internet Protocol) over several coexisting wireless protocols, thus thesame IP user identity (e.g., Bluetooth, Wi-Fi, etc.) may not have anycommon identity shared across radio platforms. In such heterogeneousenvironments, a connection must be established to link the higherIP-based user identity with lower radio layer attributes.

Context information may include, but is not limited to: identity of theUE, radio resources (such as component carriers (CC), frequency hands,time slots, etc.), paging channel capabilities, last connected eNB(within the TA), listing of nearby eNBs, listing of eNBs of the TA,geographic data, received signal quality indicators, nearby cellidentification, etc. In one minimal case, the context informationconsists of the identity of the UE, and the active CC.

In the exemplary embodiment, the mobile device provides its contextinformation to the base station; however other radio networktechnologies may have bi-directional context information exchanges.Also, it will be appreciated that other types of context information maybe substituted; the foregoing being merely illustrative. The manner andtypes of context information substituted are readily determined by thoseof ordinary skill in the art given the contents of the presentdisclosure.

In one embodiment, the context information is stored within the basestation, using an internal database. Complementary databases may be usedfor mobile devices. In alternate embodiments, the context informationmay also be forwarded or messaged to other network entities, includingnearby base stations, central network management entities, etc. Thecontext information is generally static; however in some scenarios,various context information may dynamically change, and require updating(e.g., periodically or in response to the occurrence of a particularevent). The context information is used and monitored by each of theapparatus to determine and/or update paging agreements. For example, abase station may track context information of multiple UEs to constantlyoptimize its radio resource utilization. Such variations would enableeNBs to track contexts balance UEs among CCs. Also, mobile devices maytrack context information for multiple eNBs, and selectively enter intoagreements with other base stations.

In one implementation, an acknowledgment message is responsivelytransmitted to ensure that all parties are in agreement on contextinformation. For example, once a base station has received contextinformation from a mobile device, the base station transmits anacknowledgment message, indicating reception of the context informationand finalizing a paging agreement. In some variants, the acknowledgementindicates acceptance of the message content, or alternately, selectionof one or more context options.

Step 804 ends when the participant parties of the paging notificationmechanism are in initial agreement (implicitly or explicitly) as to thepaging agreement.

At step 806, the participant parties refresh the paging agreement toensure continued agreement on the terms. In one exemplary embodiment,the paging agreement is refreshed using a periodic refresh message. Ifthe refresh message is received within an expected period, then thepaging agreement is renewed. If however, the refresh message is notreceived within the expected period, then the paging agreement isconsidered invalid. In one such variant, the paging agreement isthereafter discontinued, and the process automatically continues to step808 to delete related records. In another such variant, the pagingagreement is revived, and the process repeats step 806. The pagingagreement may also be affirmatively discontinued (e.g., with an explicitmessage, which may include reasons or codes if desired).

As noted above, one embodiment of the invention refreshed the pagingagreement at periodic or known intervals or time slots. For example, inthe aforementioned scenario, the second base station sets a simple“watchdog” countdown timer having a first refresh period N. The firstmobile device transmits a refresh message before the expiration of thewatchdog timer. The first mobile device may use a periodic “heartbeat”timer having a second period O. Alternately, the mobile device may usean aperiodic refresh scheme (provided that the aperiodic refresh messagesatisfies the N period constraints).

Various systems may further dynamically update the refresh period N. Forinstance, in dynamically changing radio environments, the period N maybe shortened for high noise environments, whereas low noise or stableenvironments may lengthen the period N. In systems which do not maintaina connection, the changing parameters (such as the N period) may thebroadcast via other broadcast control channels (e.g., embedded within aSystem Information Block (SIB), Master Information Block (MIB), etc.).

Generally, shortening or lengthening of the refresh period N, alsoaffects the second period O. The manner of the effect may or may not bedirectly related. For example, the mobile device may select a value O,shorter than N, but optimized for power consumption (e.g., minimizingthe number of refresh messages sent). In contrast, the mobile device mayselect a value O for robustness to provide multiple refresh attemptsbefore the expiration of the base station timer period N.

In other embodiments, the mobile device may transmit the refresh messageirregularly or aperiodically, such as in an event-triggered manner. Forinstance, in one exemplary system, the mobile device only transmits arefresh message when triggered or queried by the base station. The basestation may periodically broadcast a refresh request message; inresponse thereto, each mobile station within range transmits a refreshmessage. Alternatively, for paging notification systems where the basestation and mobile station retain an active radio link connection, thebase station transmits a refresh request message, and the mobile stationtransmits the refresh message.

In other variations, the refresh message may be triggered, based onother factors, such as environmental channel conditions, population ofmobile devices, etc. For example, a mobile device may passively monitorbroadcast channels (such as a pilot channel). When reception of thepilot channel fluctuates, refresh messages are resent. In anotherexample, a base station may consider the number of close by mobiledevices. As the number of mobile devices increases or decreases, thebase station may request refreshes from nearby mobile devices, to prunedevices which have fallen out of reception.

In yet another variation, the paging agreement is assumed valid unless apaging channel message is missed. Thus, a mobile device and base stationagree on a paging agreement, which is assumed valid until provenotherwise. If the mobile device does not respond to a paging channelmessage, then the base station invalidates the paging agreement.

As previously mentioned, if the refresh message is not received withinthe expected period, then the paging agreement is invalid. However, insome embodiments, a revival procedure may be executed in optional step807. If the system does not support revival, then the processimmediately skips to step 808. Moreover, while generally it is easierfor the transmitting party (e.g., base station) to determine that thepaging agreement is invalid (due to a missed page, etc.), this does notpreclude the receiving party (e.g., mobile device) from determining thatthe paging agreement is invalid. For example, a mobile device canmonitor the nearby pilot channels. If a mobile device loses pilotchannel reception, then the mobile device may safely assume that thepaging channel would also be lost (the pilot channel is typically theeasiest channel to receive). If the mobile device should happen toreacquire the pilot channel, it may proceed to step 807, to proactivelyrevive the paging agreement.

At step 807, attempts are optionally made to revive a previously lost orinvalid paging agreement. In one embodiment, the base station attemptsmultiple page messaging retries. After the watchdog timer has expired,the base station transmits a second paging channel message and restartsa restart timer P. At the expiration of the P timer, another retry maybe attempted. The paging channel retries may be attempted any number oftimes; however, a maximum number of retries may prevent excessivenetwork congestion.

In other embodiments, the community of base stations may switch to alegacy paging mode. For example, if the first base station is unable topage the mobile device, the base station may flag other base stations ofthe tracking area. Subsequently thereafter, the entire tracking arearesumes legacy paging operation.

In a mobile device-initiated embodiment, the mobile device may transmita refresh or update message upon re-engagement with a previously knownbase station. The base station resumes paging agreement operation, if itreceives any out-of-sequence messaging.

Upon successful revival, the participants return to step 806.Unsuccessful revival attempts eventually proceed to step 808. Yet othermethods and schemes for revival will immediately be recognized bypersons of ordinary skill in the art, given the contents of thisdisclosure.

At step 808, the paging agreement is discontinued. In one embodiment,one or more parties of the paging agreement delete the paging agreement.For example, the base station may delete paging agreement for a mobiledevice. Thereafter, the mobile device must reinitiate a paging agreementwith the base station. In other embodiments, the context information maybe reserved for possible revival. For example, a mobile device may beable to revive its connection with the base station, if the base stationcan retrieve previously invalid context information, even if no currentpaging agreement exists.

One exemplary paging agreement transaction 900 is diagrammed in FIG. 9,further illustrating the paging agreement between multiple parties in acellular radio system. As shown, the exemplary system includes a firstUE A 1500, a first eNB1 1200, and a second eNB2 1200. The first UE Aidentifies nearby cellular base stations (for example, based on a pilotsignature, etc.) at a first time 902. In the illustrated example, UE Apreferentially selects the first eNB1 for exchanging contextinformation, and paging agreement.

The UE A 1500 transmits a first update message to the first eNB1 1200(904), the update message containing context information. The eNB1stores the context information, generates a paging agreement and startsa watchdog timer (having a period T2). The first eNB1 also transmits anacknowledgement to the first UE A, formalizing the paging agreement.Periodically (every T1 where T1 is shorter than the base station'swatchdog tinier), the UE A transmits a refresh message (906).

At a later time 908, the first UE A detects a second base station eNB2(or determines that the second base station is more desirable than thefirst base station). The UE A initiates a paging agreement with thesecond eNB2 (1200). Shortly thereafter, the UE A stops refreshing thepaging agreement. Once the watchdog timer expires, the first basestation eNB1 terminates the context information and paging agreement.

Context Information Based Paging—

FIG. 10 illustrates one embodiment of the invention, specificallycharacterizing methods of paging channel operation that exploit devicecontext information. In the following discussion, one or more secondbase station devices receive a network page from a network entity (suchas a Mobility Management Entity (MME) 604). In response, each of thebase stations individually determines if it should transmit a pagingchannel message to the mobile device. In some implementations, themobile device receives paging channel messages from multiple basestations. The first unique paging message may be answered, whereassubsequent duplicative paging messages are ignored. In alternateembodiments, the mobile device may selectively respond one of thereceived paging messages, preferentially (e.g., such as to improvesignal quality, match device considerations, optimize serviceconsiderations, etc.).

The network page and network entity may be optionally modified foroperation with the disclosed base stations. In one embodiment, the basestation determines the appropriate response without further consultingexternal network entities. In contrast, it is appreciated that the basestation may have supplemental interfaces, or modified interfaces withfuture network devices, so as to further improve network operation.

Moreover, while the following process is described in the context of acellular network, it is appreciated that the process is equallyadaptable to other wireless protocols, and systems. In fact, it isenvisioned that heterogeneous network structures may be configured tosupport a unique identity responding to multiple radio accesstechnologies. The following process appropriately allows each of themixture of access points to independently transmit paging messages tothe device.

At step 1002 of the method 1000 of FIG. 10, the one or more pagetransmitting devices receive a network page from a central networkauthority. In one exemplary embodiment each eNB 1200 of a specifiedtracking area receives a network page from a MME 604. Alternatively, thenetwork page may be forwarded from a peer entity (e.g., similar to arerouting mechanism). For example, a first base station of a trackingarea may enable other base stations (that have less recent contextinformation) for secondary paging transmission retries.

At step 1004, the page transmitting device considers the network pagewith reference to an internal database of context information. Theinternal database of context information returns corresponding contextinformation (if available) and any paging agreements (if valid), whenprovided with a device specific identifier. Consequently, if the networkpage addresses a device specific identifier that has a valid pagingagreement, then the base station generates the paging channel message inaccordance with the context information (step 1006). If the network pagedoes not return a current paging agreement, then the page transmittingdevice ignores the network page (step 1008).

At step 1006, the page transmitting device transmits the paging channelmessage. In one embodiment, successful response to the paging channelmessage (i.e., the page receiving device answers), refreshes the pagingagreement. Successful response restarts the watchdog timer. In otherimplementations, successful response to the paging channel message isdistinct from refreshing the paging agreement. Unsuccessful pagetransmission may also be used as a precondition or trigger for reversionto legacy paging operation, or alternatively triggering revival of thepaging agreement.

In contrast to step 1006, during step 1008, the page transmitting deviceignores the network page. In one embodiment, the network page is queuedfor subsequent transmission in the event of a failure. For example, ifthe initial attempts by a primary base station fail, other secondarybase stations may transmit the same paging message to augment theprimary base station. In another example, the paging mechanisms of thepresent invention revert to legacy operation (all base stations of theTA), if the paging mechanism fails.

One exemplary paging channel transaction 1100 according to the inventionis diagrammed in FIG. 11, depicting the paging channel transactions of amobile device using multiple base stations in a cellular radio system.As shown, the exemplary system includes a first UE A 1500, a first eNB11200A, a second eNB2 1200B, a third eNB3 1200C, and a central networkauthority MME. The first, second, and third base stations are addressedas a tracking area. Initially, the UE A negotiates a paging agreementwith the first eNB1 (see e.g., the procedure 900 of FIG. 9).

The MME 604 receives data addressed to the first UE A. The MME 604generates a network page for UE A 1500, and transmits the network page610 to the current tracking area (eNB1, eNB2, eNB3); each base stationof the tracking area receives a paging request. Responsively, each basestation checks for a valid paging agreement, and uses correspondingcontext information to generate the paging channel message 612. As shownin FIG. 11, only the first eNB1 1200A transmits the paging channelmessage 612. During the message exchange UE A and eNB1 have an activedialog, thus in this example, the watchdog timers can be suspended(i.e., the paging agreement remains valid). Once the connection has beenreleased, the paging agreement watchdog timers are resumed.

Exemplary Base Station Apparatus—

Referring now to FIG. 12, exemplary base station apparatus 1200 usefulin implementing the functionality previously described above isillustrated and described. The base station apparatus 1200 of theillustrated embodiment generally takes the form factor of a stand-alonedevice for use in a cellular network, although other form-factors (e.g.,femtocells, picocells, access points, components within other hostdevices, etc.) are envisaged as well. The apparatus of FIG. 12 includesone or more substrate(s) 1202 that further include a plurality ofintegrated circuits including a processing subsystem 1204 such as adigital signal processor (DSP), microprocessor, PLD or gate array, orplurality of processing components, RF transceiver(s), as well as apower management subsystem 1206 that provides power to the base station1200.

The processing subsystem 1204 includes in one embodiment an internalcache memory, or a plurality of processors (or a multi-core processor).The processing subsystem 1204 is preferably connected to a non-volatilememory 1208 such as a hard disk drive (HDD), as well as a memorysubsystem which may comprise SRAM, Flash, SDRAM, etc. The memorysubsystem may implement one or a more of DMA type hardware, so as tofacilitate rapid data access.

The exemplary apparatus 1200 will, in some embodiments, implement someform of broadband access. In the illustrated embodiment, the broadbandaccess is provided by a DSL connection (i.e., via DSL subsystem 1210),although other interfaces, whether wired or wireless, may be used inplace of or in combination with the DSL subsystem 1210 shown. Thedigital portion of DSL processing may either be performed in theprocessor 1204, or alternatively in a separate DSL processor (notshown). Further, while a DSL broadband connection is illustrated, it isrecognized by one of ordinary skill that other broadband access schemessuch as DOCSIS cable modem, T1 line, WiMAX (i.e., IEEE Std. 802.16),ISDN, FiOS, microwave link, satellite link, etc. could be readilysubstituted or even used in tandem with the aforementioned DSLinterface. DSL has the advantage of being low cost and generallyubiquitous, and carried over copper-based telephony infrastructure whichis currently widely distributed throughout the population.

In one exemplary embodiment, the base station should seamlessly operatewith legacy MME apparatus 604 of the core network. In one suchembodiment, the base station and MME are connected via the broadbandtype interface 1210.

The base station apparatus 1200 also includes one or more RF modemsubsystems. The modem subsystems 1212 enable the base station to provideservice to one or more subscriber devices. It is readily appreciatedthat in some implementations of the invention, multiple subsystems maybe required. For example, a base station may provide multiple RF modemsubsystems to provide, inter alia, multi-mode operation (e.g. GSM, GPRS,UMTS, and LTE) over multiple distinct air interfaces. The modemsubsystems 1212 include a digital modem, RF frontend, and one or moreantennas.

It is further noted that in some embodiments, it may be desirable toobviate some of the components presently illustrated (such as RFfrontend), or alternatively, the discrete components illustrated may bemerged with one another to form a single component.

As noted above, exemplary implementations of the invention utilizepaging agreement and context information for optimized paging channeloperation. In one such implementation, a paging agreement including oneor more context information details is referenced to a unique orsemi-unique user identity. For instance, the base station receives anupdate message via the wireless interface. FIG. 13 illustrates oneexemplary update message 1300 containing: (i) mobile device identity1302, (ii) hardware version 1304, (iii) one or more suggested ComponentCarriers 1306, etc.

The base station generates a paging agreement by selecting a set ofparameters from the context information. In other variants, the basestation accepts or overrides default parameters.

FIG. 14 illustrates one exemplary acknowledgement message containing:(ii) paging agreement version 1402, (iii) refresh timer period 1404,(iv) one or more Component Carriers 1406, (v) intended mobile device ID1408, etc. FIG. 14A illustrates one exemplary paging agreement entry1450 stored at the eNB. The paging agreement entry includes the (i) UEID 1452, (ii) cell ED 1454 (if several cells are operated by the eNB),(iii) selected CC 1456, (iv) the watchdog timer period 1458, and (v) anoptional refresh time period 1460.

In some simple variants, the acknowledgement message is an acceptance ordenial of the context information.

The base station apparatus stores the paging agreement and relatedcontext information within an internal database, referenced by mobiledevice identity. The entries of the database are valid for use,according to a watchdog timer (set to the refresh timer period). Thewatchdog timer operation is set and reset, responsive to “heartbeat”messaging from the associated mobile device. In some configurations, ifthe watchdog timer has expired, the entries are deleted. In alternateconfigurations, the expiration of the timer triggers revival attempts.

The base station apparatus 1200 of FIG. 12 further includes apparatusfor conditional paging transmissions for a mobile device, based on thevalidity and contents of the internal database. Responsive to receivinga network page from the MME 604 (coupled to the network interface 1210),the base station apparatus references the internal databases forcurrent, valid records having the same unique or semi-unique mobiledevice identifier. If a suitable record exists, then the base stationapparatus generates and transmits a paging channel message in accordancewith the appropriate context information, (e.g., specified ComponentCarriers, etc.)

Other variants of the internal database operation, timerimplementations, context information, and conditional pagingtransmissions are readily implemented by an artisan of ordinary skill,given the present disclosure.

Exemplary Mobile Apparatus—

Referring now to FIG. 15, exemplary client or UE apparatus 1500implementing the methods of the present invention is illustrated. Asused herein, the terms “client” and “UE” include, but are not limited tocellular telephones, smartphones (such as for example the iPhone™ devicemanufactured by the Assignee hereof), personal computers (PCs), such asfor example an iMac™, Mac Pro™, Mac Mini™ or MacBook™, andminicomputers, whether desktop, laptop, or otherwise, as well as mobiledevices such as handheld computers, PDAs, personal media devices (PMDs),such as for example an iPod™, or any combinations of the foregoing. Theconfiguration of paging channel reception is preferably performed insoftware, although firmware and/or hardware embodiments are alsoenvisioned.

The UE apparatus 1500 includes a processor subsystem 1502 such as adigital signal processor, microprocessor, field-programmable gate array,or plurality of processing components mounted on one or more substrates1504. The processing subsystem may also comprise an internal cachememory. The processing subsystem 1502 is connected to a memory subsystem1506 comprising memory which may for example, comprise SRAM, flash andSDRAM components. The memory subsystem may implement one or a more ofDMA type hardware, so as to facilitate data accesses as is well known inthe art.

The radio/modem subsystem 1508 comprises a digital baseband, analogbaseband, TX frontend and RX frontend. The apparatus 1500 furtherincludes an antenna assembly; the selection component may comprise aplurality of switches for enabling various antenna operational modes,such as for specific frequency ranges, or specified time slots. Whilespecific architecture is discussed, in some embodiments, some componentsmay be obviated or may otherwise be merged with one another (such as RFRX, RF TX and ABB combined, as of the type used for 3G digital RFs) aswould be appreciated by one of ordinary skill in the art given thepresent disclosure.

The analog baseband typically controls operation of the radio frontendstherefore; the digital baseband modem loads the analog baseband withparameters for the reception of paging channel messages. The selectioncomponent may be controlled by the analog baseband to receive pagingchannel messages to offload such controlling functions from the digitalbaseband modem.

The illustrated power management subsystem (PMS) 1510 provides power tothe UE, and may comprise an integrated circuit and or a plurality ofdiscrete electrical components. In one exemplary portable UE apparatus,the power management subsystem 1006 advantageously interfaces with abattery.

The user interface system 1512 includes any number of well-known I/Oincluding, without limitation: a keypad, touch screen, LCD display,backlight, speaker, and microphone. However, it is recognized that incertain applications, one or more of these components may be obviated.For example, PCMCIA card type UE embodiments may lack a user interface(as they could piggyback onto the user interface of the device to whichthey are physically and/or electrically coupled).

The apparatus 1500 further includes optional additional peripherals 1514including, without limitation, one or more GPS transceivers, or networkinterfaces such as IrDA ports, Bluetooth transceivers, USB, Firewire,etc. It is however recognized that these components are not required foroperation of the UE in accordance with the principles of the presentinvention.

In the illustrated embodiment, the modem subsystem 1508 additionallyincludes subsystems or modules for: requesting paging agreements,refreshing paging agreements, and selectively receiving paging messagesin accordance with the paging agreement. These subsystems may beimplemented in software or hardware, which is coupled to the radio modemsubsystem. Alternatively, in another variant, the subsystems may bedirectly coupled to the processing subsystem 1502.

An exemplary UE is configured to transmit an update messages thatincludes current context information; the update message facilitatesgeneration of a paging agreement. Subsequently thereafter, the UEreceives a paging agreement, based on the transmitted contextinformation. The accepted paging agreement is used for further operation(see previously referenced FIGS. 13 and 14).

In one exemplary embodiment, the UE apparatus configures its pagingchannel reception in accordance with the paging agreement and relatedcontext information. Once the UE apparatus has received the pagingagreement, a “heartbeat” timer is set to periodically transmit refreshmessages, to extend the current paging agreement. If the UE shoulddesire termination of the paging agreement, the UE simply refuses totransmit the heartbeat. In yet other embodiments, the heartbeat messagemay include other context information, or supplemental updates, for thebase station's internal database.

During operation, the UE apparatus can optimize paging channel receptionto the resources and scheduling of the paging agreement. In oneexemplary implementation, the UE may only check a subset of all possibleComponent Carriers. Other variants of the timer implementations, contextinformation, and conditional paging channel reception are readilyimplemented by an artisan of ordinary skill, given the presentdisclosure.

Business Methods and Rules—

It will be recognized that the foregoing network apparatus andmethodologies may be readily adapted to various business models.

In one business paradigm, appropriately configured user equipment (e.g.,UE 1500) may receive enhanced paging messages, and may efficientlymonitor existing paging channels, thus increasing the overall perceivedquality of experience. In one such embodiment, a dedicated subset ofpaging channels are allocated to enabled UEs. Thus while, legacy devicescontinue to broadly monitor all paging channels (in a comparativelyinefficient manner), UE devices 1500 according to the invention onlymonitor the designated subset of paging channels. This approach ismarkedly more efficient, and significantly improves power consumption,thereby leading to enhanced user experience and differentiation overcompeting products.

The aforementioned network apparatus and methodologies may also bereadily adapted for operation in accordance with an underlying businessrules algorithm or “engine”. This business rules engine may comprise forexample a software application (and/or firmware or even hardwareaspects), and is implemented in one embodiment as a separate entity atthe base station. A business rules engine may find particular benefit infemtocell deployments (e.g., as part of an enhanced offering by a smallbusiness concern, or residential equipment). The rules engine is ineffect a high-layer supervisory process which aids the base stationoperator (or other interested party) in making operational decisions orresource allocations based on important criteria such as financialaspects, user experience enhancement, etc.

In one embodiment, the business rules engine is configured to take intoaccount the revenue and/or profit implications associated with providingresources to one or more users. Accordingly, the exemplary businessrules engine can modify the paging channel behaviors of the system tosupport a wider base of users (e.g. using fewer CC slices per user) oralternatively, legacy support or robust operation (e.g. allocating moreCC slices per user).

For instance, in one example, evaluation of the requests from apopulation of users for resources (e.g., frequency spectrum) may includean analysis of the incremental cost, revenue, and/or profit associatedwith the various allocation options. In some cases, the network providermay determine that new service requests are uncommon, and thus paging isloss important. In other cases, the network provider may determine thatnew users and services are frequently entering and exiting a cell, thusrequiring an allocation of more paging resources. These “business rules”may be imposed e.g., at time of resource request, and then maintainedfor a period of time (or until an event triggering a re-evaluationoccurs), or alternatively according to a periodic model.

Myriad other schemes for implementing dynamic allocation of resourceswill be recognized by those of ordinary skill given the presentdisclosure.

It will be recognized that while certain aspects of the invention aredescribed in terms of a specific sequence of steps of a method, thesedescriptions are only illustrative of the broader methods of theinvention, and may be modified as required by the particularapplication. Certain steps may be rendered unnecessary or optional undercertain circumstances. Additionally, certain steps or functionality maybe added to the disclosed embodiments, or the order of performance oftwo or more steps permuted. All such variations are considered to beencompassed within the invention disclosed and claimed herein.

While the above detailed description has shown, described, and pointedout novel features of the invention as applied to various embodiments,it will be understood that various omissions, substitutions, and changesin the form and details of the device or process illustrated may be madeby those skilled in the art without departing from the invention. Theforegoing description is of the best mode presently contemplated ofcarrying out the invention. This description is in no way meant to belimiting, but rather should be taken as illustrative of the generalprinciples of the invention. The scope of the invention should bedetermined with reference to the claims.

What is claimed is:
 1. A method of paging a mobile device from a basestation in a wireless network based on a selected resource used by themobile device to receive a paging channel, the method comprising:selecting, by the base station, a resource to be used by the mobiledevice to receive paging information, sending the paging information tothe mobile device from the base station using only a paging channel ofthe selected resource; generating a paging agreement between the mobiledevice and the base station; and refreshing the paging agreement using aperiodic refresh message.
 2. The method of claim 1, wherein the selectedresource comprises at least one component carrier (CC).
 3. The method ofclaim 1, wherein the selected resource used by the mobile device toreceive the paging channel is used in an idle mode.
 4. The method ofclaim 1, wherein the information transmitted by the mobile devicecomprises context information for the mobile device, said contextdescription comprises a description of at least one paging resourceavailable to the mobile device.
 5. The method of claim 1, wherein thepaging information comprises an acknowledgement message from the basestation.
 6. A base station apparatus, comprising: a digital processor; aradio interface in data communication with the processor; and a storagedevice in data communication with the processor, the storage devicecomprising computer-executable instructions that, when executed by thedigital processor cause the base station to: select a resource to beused by the mobile device to receive paging information, send the paginginformation to the mobile device from the base station using only apaging channel of the selected resource; generate a paging agreementbetween the mobile device and the base station; and refresh the pagingagreement using a periodic refresh message.
 7. The apparatus of claim 6,wherein the base station comprises an LTE-compliant eNodeB, and themobile device comprises an LTE-compliant UE.
 8. The apparatus of claim7, wherein the selected resource comprises at least one componentcarrier (CC).
 9. The apparatus of claim 8, wherein the base stationcomprises an LTE-A (Long Term Evolution-Advanced)-compliant eNodeB whichis configured to support a 20-MHz maximum bandwidth for the at least onecomponent carrier.
 10. The apparatus of claim 6, wherein the basestation comprises an LTE-A (Long Term Evolution-Advanced)-complianteNodeB which is backward-compatible with at least one legacy LTE (LongTerm Evolution) paging resource.
 11. The apparatus of claim 6, whereinthe selected resource used by the mobile device to receive the pagingchannel is used in an idle mode.
 12. The apparatus of claim 6, whereinthe information transmitted by the mobile device comprises contextinformation for the mobile device, said context description comprises adescription of at least one paging resource available to the mobiledevice.
 13. The apparatus of claim 6, wherein the paging informationcomprises an acknowledgement message from the base station.
 14. AnLTE-compliant eNodeB base station that performs the method of claim 1.15. The base station of claim 14, wherein the base station comprises anLTE-A (Long Term Evolution-Advanced) compliant eNodeB which isconfigured to support a 20-MHz maximum bandwidth for the at least onecomponent carrier.
 16. The base station of claim 14, wherein the basestation comprises an LTE-A (Long Term Evolution-Advanced) complianteNodeB which is backwards-compatible with at least one legacy LTE (LongTerm Evolution) paging resource.
 17. The method of claim 1, wherein ifno selected resource information exists, no paging information is sentto the mobile device.
 18. A base station apparatus of claim 6, whereinif no selected resource information exists, no paging information issent to the mobile device.